A boolean value indicating whether labels at major tic positions of an
item-axis in
a chart-widget will wrap at
spaces. The default value
is t. Wrapping will be done only if the
major-label-angle property is
zero.

If true, then each major tic label will wrap to a new line of text at
every space in the label string. The widget will automatically leave
enough room to display the label that requires the most lines of text.

An alternative is to set this property to nil
and then embed newline characters in the strings returned by the
on-print-major-label function
of the chart-axis.